'World's oldest fossil forest' discovered in cliffs on Devon and Somerset coastline

Scientists have uncovered what they believe to be the world’s oldest fossil forest in high sandstone cliffs along the Devon and Somerset coastline.

The fossilised trees which date back 390 million years are palm-like in appearance but would have had thin trunks with hollow centres, researchers say.

This forest is around four million years older than the previous record-holder, which was found in a sandstone quarry in the town of Cairo, New York state.

Its remains were discovered in the Hangman Sandstone Formation near Minehead.

Researchers said these ancient plants – called Calamophyton – would have been prototypes of modern-day trees.

They would also have been qui te short, somewhere between two and four metres tall, with branches covered in hundreds of twig-like structures instead of leaves.

Professor Neil Davies, from the University of Cambridge’s Department of Earth Sciences, said: "This was a pretty weird forest – not like any forest you would see today.

"There wasn’t any undergrowth to speak of and grass hadn’t yet appeared, but there were lots of twigs dropped by these densely packed trees, which had a big effect on the landscape."

The forest belongs to a geological time period known as the Devonian Period, between 419 million and 358 million years ago. It was a time when marine animals started to diversify and seed-bearing plants first appeared.

Professor Davies added: "The Devonian period fundamentally changed life on Earth.

"It also changed how water and land interacted with each other, since trees and other plants helped stabilise sediment through their root systems, but little is known about the very earliest forests.

"Alongside fossilised plants, the team also identified plant debris, fossilised tree logs and traces of roots – all preserved within the sandstone."

Another researcher, Christopher Berry, from Cardiff’s School of Earth and Environmental Sciences, said: "When I first saw pictures of the tree trunks, I immediately knew what they were, based on 30 years of studying this type of tree worldwide.

"It was amazing to see them so near to home. But the most revealing insight comes from seeing, for the first time, these trees in the positions where they grew."

Scientists had previously assumed this stretch of coast in south-west England did not contain significant plant fossils.

The researchers say their findings, published in the Journal of the Geological Society, show how ancient trees stabilised riverbanks and coastlines hundreds of millions of years ago.

Professor Davies said: "The evidence contained in these fossils preserves a key stage in Earth’s development, when rivers started to operate in a fundamentally different way than they had before, becoming the great erosive force they are today.

"People sometimes think that British rocks have been looked at enough, but this shows that revisiting them can yield important new discoveries."